Method and Device for Producing Photovoltaic Modules

ABSTRACT

An apparatus and a method for automatically joining components of photovoltaic elements are disclosed. The apparatus includes: a) at least two manufacturing lines and at least two assembly bridges for joining the substrates, films and glass panes, b) a stacking device for film feeding and a conveyor belt for feeding the glass panes, c) devices for centering and suctioning the films and the glass plates, d) devices for transporting and fixing the film transport frame and the glass transport frame e) devices for lowering the films and the glass plates from the respective transport frames, and f) devices for further transport.

This patent application is a national phase filing under section 371 ofPCT/IB2009/007059, filed Aug. 18, 2009, which claims the priority ofGerman patent application 10 2008 036 274.3, filed Aug. 4, 2008, each ofwhich is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The invention relates to the automatic production of a photovoltaicmodule.

BACKGROUND

Modern glass facades are often not just a function element of astructural body, but are increasingly also used for solar electricitygeneration. Tailor-made solar modules allow accurately fittingintegration in construction grids and profiles. Semitransparent solarcells, or else opaque solar cells with transparent areas, makephotovoltaic glazing systems appear as if light is flooding throughthem. In this case, the solar cells frequently provide the desiredeffect of solar and dazzling protection.

The production of such photovoltaic installations requires workingconditions such as those which are normally used in particular for theproduction of semiconductors and integrated electronic circuits.Therefore, the production of photovoltaic installations is stillrelatively expensive. There is therefore an aim to produce photovoltaicelements in large batches, and thus to reduce the costs. Considered fromthe outside, a photovoltaic module represents the connection of asubstrate panel composed of glass, a photovoltaic element and a glasspane as covering glass by means of a film which adhesively bonds theseglass panes under the influence of heat.

DE 10 2004 030 411 A1 discloses a photovoltaic element such as this, asolar module as laminated safety glass.

One object of this laid-open specification is to provide solar moduleshaving the characteristics of laminated safety glass systems using filmsbased on polyvinyl butyral (PVB).

This object is achieved by means of a solar module as laminated safetyglass, comprising a laminate of

a) a glass pane,

b) at least one solar cell unit which is arranged between two filmsbased on PCB, and

c) a cover at the rear,

characterized in that

at least one of the PVB-based films has a tear resistance of at least 16N/mm².

This document does not describe how an element such as this is intendedto be produced in large batches.

SUMMARY OF THE INVENTION

The apparatus according to an embodiment of the invention and the methodaccording to an embodiment of the invention are ensuring the productionof a photovoltaic module, that is to say the joining of correspondingcomponents, on an automatically controlled basis, reliably andcost-effectively from all respects, with short cycle times.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described in more detail in thefollowing text with reference to figures in which:

FIG. 1: shows a perspective view of a placement bridge,

FIG. 2: shows a placement bridge with production lines,

FIG. 3: shows a perspective view of the film placement,

FIG. 4: shows a perspective view of the glass placement,

FIG. 5: shows a detailed view of a centering apparatus,

FIG. 6: shows an illustration of the film centering on the stackingtable,

FIG. 7: shows an illustration of the centering of a glass pane, and

FIG. 8: shows an illustration of the film centering on the transportframe.

The following list of reference symbols may be used in conjunction withthe drawings:

-   (1) Gantries (base frames)-   (2) Main rail supports-   (3) Film transport frame-   (4) Glass transport frame-   (5) Production line 1-   (6) Production line 2-   (7) Conveyor belt for glass pane supply-   (8) Stacking table for film supply-   (9) Supply and control line channel-   (10) Servo drive for film transport device-   (11) Omega drive and centering device for film-   (12) Drive for vertical lifting movement-   (13) Centering opening for centering pin (line 1)-   (14) Sensor for film detection-   (15) Vacuum-pressure pump-   (16) Vacuum-pressure suckers-   (17) Servo drive for glass transport device-   (18) Omega drive and centering device for glass-   (19) Centering opening for centering pin (line 2)-   (20) Drive (toothed belt)-   (21) Guide rollers for omega drive-   (22) Toothed belt-   (23) Sliding rollers for centering pin-   (24) Centering pin-   (25) Linear-movement cylinder for centering pin-   (26) Film centering on the stacking table-   (27) Film centering on the suction frame-   (28) Suction openings for film transport frame-   (29) Centering device for glass pane-   (30) Drives for centering device-   (31) Conveyor belts-   (32) Drive for conveyor belts-   (A) Placement bridge-   (B) Placement bridge

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the present case, a photovoltaic module consists of a so-calledsubstrate, that is to say a glass pane with a photovoltaically actingcoating, a film placed on it and a further glass pane as a cover, theso-called bottom glass. The film is in this case in the form of aso-called melting film, which produces the connection between two glasspanes in a heating process.

These three elements are joined using the apparatus according to anembodiment of the invention.

During this process, substrate panels are moved to correspondingproduction lines, which on the one hand are fitted with a film withmatched clock times, and on the other hand are in turn covered by afurther glass pane.

FIG. 1 shows a perspective view of a placement bridge which has beendeveloped for this purpose. This essentially comprises main railsupports (2) which are supported on gantries (1). Only four gantries (1)are shown in the example in FIG. 1 although even further gantries (1)can be inserted in the center if the main rail supports (2) need to belengthened.

A film transport frame (3) is shown on the left-hand side of theillustrated placement bridge, and a glass transport frame (4) can beseen on the right-hand side.

FIG. 2 shows a placement bridge linked to a production line 1 (5) and aproduction line 2 (6) in the form of a cross section in the upper part,and in the form of a plan view in the lower part. The central area ofthe two figure elements is in this case shown interrupted in order toindicate the option of being able to insert further production lines atthis point. A stacking table (8) for the film supply is shown on theleft-hand side, while a conveyor belt (7) for the glass pane supply isillustrated on the right-hand side. The required substrates, the glasspanes with the photovoltaically acting coating, are delivered on therespective production line (5, 6). The process of joining a photovoltaicmodule consists of first of all applying a film to a substrate and thena glass pane, a so-called bottom pane, such that they fit accurately.

FIG. 3 shows a perspective view of the film placement. The two gantries(cf. also FIG. 1) which are installed in this area can be seen, with twomain rail supports (2), as the supporting apparatus for the entire filmtransport unit, one of which two main rail supports (2) is shown in moredetail. The film transport frame (3) is suspended under the two mainrail supports (2), and is moved closer to the two main rail supports (2)by means of the drive (12) for the vertical lifting movement, after afilm has been sucked up, in order then to be moved at this height levelto the area of a substrate panel which is waiting on a production line(1, 2). The drive for this movement is ensured by the servo drive (10),which acts on the two centering devices (11). The sensor (10) is used todetect a film on the stacking table (8). The vacuum-pressure pump (15)is provided for the processes of sucking up a film or a glass pane.

FIG. 3 shows one of the centering openings (13), which are arranged inpairs, for a centering pin in the main rail support (2), in this casefor the production line (1). These centering openings (13) are used forprecise fixing of the film transport frame (3), and ensure that a filmis lowered precisely onto the substrate located underneath it when thecentering pin of the film transport frame (3) is locked in thiscentering opening (13). The centering devices (11), which are fitted onboth sides of the film transport frame (3), are used for the process ofmovement to the relevant point in the main rail support (2) and forlowering of the centering pin (24) (cf. also FIG. 5). The channel (9)which runs over the entire longitudinal range of a bridge, holds all thesupply lines and control lines.

FIG. 4 shows the device, which corresponds to the film supply device,for supplying the glass panes by means of the glass transport frame (4).The position of the centering openings, which are annotated (19), forthe glass transport frame (4) is shown only in the rear main railsupport (2). The centering units for the glass transport apparatus,which correspond to the centering devices (11) for the film transportunit, are annotated (18). The servo drive (17), which drives the twocentering units (18), ensures the movement of the entire glass transportdevice to the corresponding production line. The vacuum-pressure suckers(16) are used to raise and firmly hold the respective glass pane.

FIG. 5 shows a detailed view of a fixing apparatus.

A main rail support (2) can be seen in the lower area here, with acorresponding opening for holding a centering pin (24). Sliding rollers(23) are provided on both sides of the centering pin (24), in order toguide it. A centering pin (24) is held and lowered via a linear-movementcylinder (25). A centering unit is driven via the drive shaft (21),which moves a toothed belt (22) which is passed over the guide rollers(21).

This design measure is used in all four centering devices (11, 18)considered and is referred to as an omega drive, because of the shape inwhich the toothed belt is guided.

FIG. 6 shows the initial centering of the films to be applied on thestacking table (8). The principle factor in this case is the filmcentering means (26) that are shown. At least two film centeringapparatuses (26) are in each case required in order to center a film.The number of them is in this case governed primarily by the size of thefilms resting thereon. The films may be placed thereon by hand or elsemay be taken from a magazine by an appropriately designed robot.

FIG. 7 shows the centering of a glass pane.

The glass panes are passed to this centering area via a conveyor belt(7) for glass pane supply, by means of the conveyor belts (31) which aredriven by the drive (32). In this case, the glass panes are centered bymeans of the centering devices (29), via the drives (30). The number ofcentering devices (29) shown corresponds to the multiplicity of possiblepane formats. An apparatus, which is not illustrated separately, foridentification of defective glass panes is also located in this area. Asa person skilled in the art will be aware, this works on the basis ofoptical detectors, and ensures that the relevant glass pane issegregated automatically in the event of a glass fault. For spacereasons, this additional apparatus may be installed in the center of aplacement bridge.

FIG. 8 shows the film centering on the transport frame (3).

In this case, the upper area of the figure shows the known main railsupports (2) and a centering device (11), which are attached to thegantry (1).

The two sensors (14) are used to detect the presence of a film. The filmis centered on the transport frame (3) by means of the centeringelements (27), with the illustrated suction openings (28) representingan entire matrix of suction openings on the film transport frame (3),which have to be activated in accordance with the format of therespective film.

The apparatus according to an embodiment of the invention not only makesit possible to produce photovoltaic elements at the same time on aplurality of production lines, but the effective control and the rapidand exact positioning of all the components of the production processfurthermore ensure simultaneous operation of at least two placementbridges A and B.

Since the apparatus according to an embodiment of the invention allowsthe processing of photovoltaic elements of different formats, numeroussensors, which are not illustrated in detail, are required to detectthese different formats and to make the appropriate adjustments to theinstallation parts.

A special control program is required for disturbance-free operation forthe production of photovoltaic elements with a high cycle rate and avariable production program, at the same time.

A high cycle rate requires a high movement speed, for which atoothed-belt drive is once again advantageously used. However, atoothed-belt drive has a relatively high positioning tolerance, althoughthis is reduced by means of the centering measures according to anembodiment of the invention.

Another possibility for a high movement speed is to use linear driveswhich, by virtue of the system, have a high positioning accuracy.However, these result in considerably greater costs.

1. An apparatus for automatic joining of the components of photovoltaicelements in a continuously running manufacturing process, whereindifferent installation parts interact in a specific sequence, theapparatus comprising: at least two production lines for clocked deliveryof the substrates; at least two placement bridges for joiningsubstrates, films and glass panes; a stacking apparatus for film supply;and a conveyor belt for glass pane supply; an apparatus for centeringand placing the films onto a film transport frame; an apparatus forcentering and placing the glass panes onto a glass transport frame (4);apparatuses for transporting and fixing of the film transport frame withrespect to the relevant production line; apparatuses for transportingand fixing of the glass transport frame with respect to the relevantproduction line; apparatuses for lowering the films from the filmtransport frame; apparatuses for lowering the glass panes from the glasstransport frame frames; and apparatuses for further transport of thejoined photovoltaic elements on the corresponding production line. 2.The apparatus as claimed in claim 1, further comprising means fordetecting faulty films and glass panes, whose results lead tosegregation of the relevant component in the event of a fault.
 3. Theapparatus as claimed in claim 1, further comprising means for detectingdifferent formats of films and glass panes, whose parameters are takeninto account for the control of the production process.
 4. The apparatusas claimed in claim 1, further comprising servo motors or linear drivesused for the drives.
 5. A method for automatic joining of substrates,films and glass panes as components of photovoltaic elements in acontinuously running manufacturing process, the method comprisingproviding at least two production lines for clocked delivery ofsubstrates; providing at least two placement bridges for joining thesubstrates, the films and the glass panes; providing a stackingapparatus for film supply, and providing a conveyor belt for glass panesupply; centering and placing the films onto a film transport frame, andplacing the glass panes, which have been centered on the conveyor beltonto a glass transport frame; transporting the films and the glass panestogether with their respective transport frames to the correspondingproduction line, and are fixed there; lowering the films and glass panesonto the associated substrates or films on the respective productionline; and transporting further the joined photovoltaic elements on thecorresponding production line.
 6. The method as claimed in claim 5,further comprising detecting faulty films and glass panes, whose resultslead to segregation of the relevant component in the event of a fault.7. The method as claimed in claim 5, further comprising detectingdifferent formats of films and glass panes, whose parameters are takeninto account for the control of the production process.
 8. The method asclaimed in claim 5, further comprising using servo motors or lineardrives for the drives.
 9. A computer program having a program code forcarrying out the method claimed in claim 5 when the program is run on acomputer.
 10. A machine-legible storage medium having the program codeof a computer program for carrying out the method as claimed in claim 5when the program is run on a computer.